المؤلفون: Rongkard, P, Kronsteiner, B, Hantrakun, V, Jenjaroen, K, Sumonwiriya, M, Chaichana, P, Chumseng, S, Chantratita, N, Wuthiekanun, V, Fletcher, HA, Teparrukkul, P, Limmathurotsakul, D, Day, NPJ, Dunachie, SJ

الوصف: Melioidosis is a neglected tropical disease with an estimated annual mortality rate of 89,000 in 45 countries across tropical regions. The causative agent is Burkholderia pseudomallei, a gram-negative soil-dwelling bacterium. In Thailand, B. pseudomallei can be found across multiple regions, along with the low-virulence B. thailandensis and the recently discovered B. thailandensis variant (BTCV), which expresses B. pseudomallei–like capsular polysaccharide. Comprehensive studies of human immune responses to B. thailandensis variants and cross-reactivity to B. pseudomallei are not complete. We evaluated human immune responses to B. pseudomallei, B. thailandensis, and BTCV in melioidosis patients and healthy persons in B. pseudomallei–endemic areas using a range of humoral and cellular immune assays. We found immune cross-reactivity to be strong for both humoral and cellular immunity among B. pseudomallei, B. thailandensis, and BTCV. Our findings suggest that environmental exposure to low-virulence strains may build cellular immunity to B. pseudomallei.

العلاقة: https://ora.ox.ac.uk/objects/uuid:05093ad0-f5de-481b-9866-1a3b9a3e24c3Test; https://doi.org/10.3201/eid2603.190206Test

الإتاحة: https://doi.org/10.3201/eid2603.190206Test
https://ora.ox.ac.uk/objects/uuid:05093ad0-f5de-481b-9866-1a3b9a3e24c3Test

المؤلفون: Kronsteiner, B, Chaichana, P, Sumonwiriya, M, Jenjaroen, K, Chowdhury, F, Chumseng, S, Teparrukkul, P, Limmathurotsakul, D, Day, N, Klenerman, P, Dunachie, S

الوصف: Diabetes mellitus (DM) is a serious global health problem currently affecting over 450 million people worldwide. Defining its interaction with major global infections is an international public health priority. Melioidosis is caused by Burkholderia pseudomallei, an exemplar pathogen for studying intracellular bacterial infection in the context of DM due to the 12‐fold increased risk in this group. We characterized immune correlates of survival in peripheral blood of acute melioidosis patients with and without DM and highlight different immune response patterns. We demonstrate the importance of circulating NK cells and show that CX3CR1 expression on lymphocytes is a novel correlate of survival from acute melioidosis. Furthermore, excessive serum levels of IL‐15 and IL‐18BP contribute to poor outcome independent of DM comorbidity. CD8+ T cells and granzyme B expression in NK cells are important for survival of non‐DM patients, whereas high antibody titers against B. pseudomallei and double‐negative T cells are linked to survival of DM patients. Recall responses support a role of γδ T‐cell‐derived IFN‐γ in the establishment of protective immunity in the DM group. Defining the hallmarks of protection in people with DM is crucial for the design of new therapies and vaccines targeting this rapidly expanding risk group.

العلاقة: https://ora.ox.ac.uk/objects/uuid:b38adf64-4474-44c0-968d-6fb368656568Test; https://doi.org/10.1002/eji.201848037Test

الإتاحة: https://doi.org/10.1002/eji.201848037Test
https://ora.ox.ac.uk/objects/uuid:b38adf64-4474-44c0-968d-6fb368656568Test

المؤلفون: Chaichana, P, Jenjaroen, K, Amornchai, P, Chumseng, S, Langla, S, Rongkard, P, Sumonwiriya, M, Jeeyapant, A, Chantratita, N, Teparrukkul, P, Limmathurotsakul, D, Day, N, Wuthiekanun, V, Dunachie, S

الوصف: Melioidosis is a major neglected tropical disease with high mortality, caused by the Gram-negative bacterium Burkholderia pseudomallei (Bp). Microbiological culture remains the gold standard for diagnosis, but a simpler and more readily available test such as an antibody assay is highly desirable. In this study, we conducted a serological survey of blood donors (n = 1,060) and adult melioidosis patients (n = 200) in northeast Thailand to measure the antibody response to Bp using the indirect hemagglutination assay (IHA). We found that 38% of healthy adults (aged 17–59 years) have seropositivity (IHA titer ≥ 1:80). The seropositivity in healthy blood donors was associated with having a declared occupation of rice farmer and with residence in a nonurban area, but not with gender or age. In the melioidosis cohort, the seropositivity rate was higher in adult patients aged between 18 and 45 years (90%, 37/41) compared with those aged ≥ 45 years (68%, 108/159, P = 0.004). The seropositivity rate was significantly higher in people with diabetes (P = 0.008). Seropositivity was associated with decreased mortality on univariable analysis (P = 0.005), but not on multivariable analysis when adjusted for age, diabetes status, preexisting renal disease, and neutrophil count. This study confirms the presence of high background antibodies in an endemic region and demonstrates the limitations of using IHA during acute melioidosis in this population.

العلاقة: https://ora.ox.ac.uk/objects/uuid:6cf76011-3193-477a-941c-3956ac4bbec6Test; https://doi.org/10.4269/ajtmh.17-0998Test

الإتاحة: https://doi.org/10.4269/ajtmh.17-0998Test
https://ora.ox.ac.uk/objects/uuid:6cf76011-3193-477a-941c-3956ac4bbec6Test

المؤلفون: Sumonwiriya, M, Paris, D, Sunyakumthorn, P, Anantatat, T, Jenjaroen, K, Chumseng, S, Im-Erbsin, R, Tanganuchitcharnchai, A, Jintaworn, S, Blacksell, S, Chowdhury, F, Kronsteiner-Dobramysl, B, Teparrukkul, P, Burke, R, Lombardini, E, Richards, A, Mason, C, Jones, J, Day, N, Dunachie, S

المساهمون: Picardeau, M

الوصف: Scrub typhus is a febrile infection caused by the obligate intracellular bacterium Orientia tsutsugamushi, which causes significant morbidity and mortality across the Asia-Pacific region. The control of this vector-borne disease is challenging due to humans being dead-end hosts, vertical maintenance of the pathogen in the vector itself, and a potentially large rodent reservoir of unclear significance, coupled with a lack of accurate diagnostic tests. Development of an effective vaccine is highly desirable. This however requires better characterization of the natural immune response of this neglected but important disease. Here we implement a novel IFN-γ ELISpot assay as a tool for studying O. tsutsugamushi induced cellular immune responses in an experimental scrub typhus rhesus macaque model and human populations. Whole cell antigen for O. tsutsugamushi (OT-WCA) was prepared by heat inactivation of Karp-strain bacteria. Rhesus macaques were infected intradermally with O. tsutsugamushi. Freshly isolated peripheral blood mononuclear cells (PBMC) from infected (n = 10) and uninfected animals (n = 5) were stimulated with OT-WCA, and IFN-γ secreting cells quantitated by ELISpot assay at five time points over 28 days. PBMC were then assayed from people in a scrub typhus-endemic region of Thailand (n = 105) and responses compared to those from a partially exposed population in a non-endemic region (n = 14), and to a naïve UK population in UK (n = 12). Mean results at Day 0 prior to O. tsutsugamushi infection were 12 (95% CI 0-25) and 15 (2-27) spot-forming cells (SFC)/106 PBMC for infected and control macaques respectively. Strong O. tsutsugamushi-specific IFN-γ responses were seen post infection, with ELISpot responses 20-fold higher than baseline at Day 7 (mean 235, 95% CI 200-270 SFC/106 PBMC), 105-fold higher at Day 14 (mean 1261, 95% CI 1,097-1,425 SFC/106 PBMC), 125-fold higher at Day 21 (mean 1,498, 95% CI 1,496-1,500 SFC/106 PBMC) and 118-fold higher at Day 28 (mean 1,416, 95% CI 1,306-1,527 SFC/106 PBMC). No ...

العلاقة: https://ora.ox.ac.uk/objects/uuid:6676d709-1305-476d-8fdb-b164b50f4c01Test; https://doi.org/10.1371/journal.pntd.0005846Test

الإتاحة: https://doi.org/10.1371/journal.pntd.0005846Test
https://ora.ox.ac.uk/objects/uuid:6676d709-1305-476d-8fdb-b164b50f4c01Test

المؤلفون: Dunachie, S, Jenjaroen, K, Reynolds, C, Quigley, K, Sergeant, R, Sumonwiriya, M, Chaichana, P, Chumseng, S, Ariyaprasert, P, Lassaux, P, Gourlay, L, Promwong, C, Teparrukkul, P, Limmathurotsakul, D, Day, N, Altmann, D, Boyton, R

الوصف: Melioidosis, caused by Burkholderia pseudomallei, is a potentially lethal infection with no licensed vaccine. There is little understanding of why some exposed individuals have no symptoms, while others rapidly progress to sepsis and death, or why diabetes confers increased susceptibility. We prospectively recruited a cohort of 183 acute melioidosis patients and 21 control subjects from Northeast Thailand and studied immune parameters in the context of survival status and the presence or absence of diabetes. HLA-B*46 (one of the commonest HLA class I alleles in SE Asia) and HLA-C*01 were associated with an increased risk of death (odds ratio 2.8 and 3.1 respectively). Transcriptomic analysis during acute infection in diabetics indicated the importance of interplay between immune pathways including those involved in antigen presentation, chemotaxis, innate and adaptive immunity and their regulation. Survival was associated with enhanced T cell immunity to nine of fifteen immunodominant antigens analysed including AhpC (BPSL2096), BopE (BPSS1525), PilO (BPSS1599), ATP binding protein (BPSS1385) and an uncharacterised protein (BPSL2520). T cell immunity to GroEL (BPSL2697) was specifically impaired in diabetic individuals. This characterization of immunity associated with survival during acute infection offers insights into correlates of protection and a foundation for design of an effective multivalent vaccine.

العلاقة: https://ora.ox.ac.uk/objects/uuid:31b09531-9e0b-4b0a-a74f-42c37e920a5eTest; https://doi.org/10.1038/s41598-017-12331-5Test

الإتاحة: https://doi.org/10.1038/s41598-017-12331-5Test
https://ora.ox.ac.uk/objects/uuid:31b09531-9e0b-4b0a-a74f-42c37e920a5eTest

المؤلفون: Chaichana, P, Chantratita, N, Brod, F, Koosakulnirand, S, Jenjaroen, K, Chumseng, S, Sumonwiriya, M, Burtnick, M, Brett, P, Teparrukkul, P, Limmathurotsakul, D, Day, N, Dunachie, S, West, T

الوصف: Background Melioidosis, caused by the flagellated bacterium Burkholderia pseudomallei, is a life-threatening and increasingly recognized emerging disease. Toll-like receptor (TLR) 5 is a germline-encoded pattern recognition receptor to bacterial flagellin. We evaluated the association of a nonsense TLR5 genetic variant that truncates the receptor with clinical outcomes and with immune responses in melioidosis. Methodology/Principle Findings We genotyped TLR5 c.1174C>T in 194 acute melioidosis patients in Thailand. Twenty-six (13%) were genotype CT or TT. In univariable analysis, carriage of the c.1174C>T variant was associated with lower 28-day mortality (odds ratio (OR) 0.21, 95% confidence interval (CI) 0.05-0.94, P = 0.04) and with lower 90-day mortality (OR 0.25, 95% CI 0.07-086, P = 0.03). In multivariable analysis adjusting for age, sex, diabetes and renal disease, the adjusted OR for 28-day mortality in carriers of the variant was 0.24 (95% CI 0.05-1.08, P = 0.06); and the adjusted OR for 90-day mortality was 0.27 (95% CI 0.08-0.97, P = 0.04). c.1174C>T was associated with a lower rate of bacteremia (P = 0.04) and reduced plasma levels of IL-10 (P = 0.049) and TNF-α (P < 0.0001). We did not find an association between c.1174C>T and IFN-γ ELISPOT (T-cell) responses (P = 0.49), indirect haemagglutination titers or IgG antibodies to bacterial flagellin during acute melioidosis (P = 0.30 and 0.1, respectively). Conclusions/Significance This study independently confirms the association of TLR5 c.1174C>T with protection against death in melioidosis, identifies lower bacteremia, IL-10 and TNF-α production in carriers of the variant with melioidosis, but does not demonstrate an association of the variant with acute T-cell IFN-γ response, indirect haemagglutination antibody titer, or anti-flagellin IgG antibodies.

العلاقة: https://ora.ox.ac.uk/objects/uuid:24c7d1cb-2842-42e6-b645-ce5764b52ff4Test; https://doi.org/10.1371/journal.pntd.0005587Test

الإتاحة: https://doi.org/10.1371/journal.pntd.0005587Test
https://ora.ox.ac.uk/objects/uuid:24c7d1cb-2842-42e6-b645-ce5764b52ff4Test

المؤلفون: Dunachie, S, Jenjaroen, K, Chumseng, S, Sumonwiriya, M, Ariyaprasert, P, Chantratita, N, Sunyakumthorn, P, Hongsuwan, M, Wuthiekanun, V, Fletcher, H, Teparrukkul, P, Limmathurotsakul, D, Day, N

الوصف: Background: Melioidosis is an increasingly recognised cause of sepsis and death across South East Asia and Northern Australia, caused by the bacterium Burkholderia pseudomallei. Risk factors include diabetes, alcoholism and renal disease, and a vaccine targeting at-risk populations is urgently required. A better understanding of the protective immune response in naturally infected patients is essential for vaccine design. Methods: We conducted a longitudinal clinical and immunological study of 200 patients with melioidosis on admission, 12 weeks (n = 113) and 52 weeks (n = 65) later. Responses to whole killed B. pseudomallei were measured in peripheral blood mononuclear cells (PBMC) by interferon-gamma (IFN-γ) ELIspot assay and flow cytometry and compared to those of control subjects in the region with diabetes (n = 45) and without diabetes (n = 43). Results: We demonstrated strong CD4+ and CD8+ responses to B. pseudomallei during acute disease, 12 weeks and 52 weeks later. 28-day mortality was 26% for melioidosis patients, and B. pseudomallei-specific cellular responses in fatal cases (mean 98 IFN-γ cells per million PBMC) were significantly lower than those in the survivors (mean 142 IFN-γ cells per million PBMC) in a multivariable logistic regression model (P = 0.01). A J-shaped curve association between circulating neutrophil count and mortality was seen with an optimal count of 4000 to 8000 neutrophils/μl. Melioidosis patients with known diabetes had poor diabetic control (median glycated haemoglobin HbA1c 10.2%, interquartile range 9.2–13.1) and showed a stunted B. pseudomallei-specific cellular response during acute illness compared to those without diabetes. Conclusions: The results demonstrate the role of both CD4+ and CD8+ T-cells in protection against melioidosis, and an interaction between diabetes and cellular responses. This supports development of vaccine strategies that induce strong T-cell responses for the control of intracellular pathogens such as B. pseudomallei.

العلاقة: https://ora.ox.ac.uk/objects/uuid:dc8e395f-298a-416f-85cd-ea4051ee4401Test; https://doi.org/10.1371/journal.pntd.0004152Test

الإتاحة: https://doi.org/10.1371/journal.pntd.0004152Test
https://ora.ox.ac.uk/objects/uuid:dc8e395f-298a-416f-85cd-ea4051ee4401Test